London: Ryan Harris backed Australia to mount a successful defence of the Ashes without him after announcing his retirement from all cricket just four days before the start of the first Test against England.
Persistent knee trouble, which has plagued him throughout his career, led the 35-year-old fast bowler to call time on his career on Saturday.
He had been due to play against Essex in Australia`s final warm-up match before the first Test starts in Cardiff on Wednesday after bowling well in the tour opener against Kent.
However, he was a late withdrawal from the side that won by 169 runs at Chelmsford on Saturday and new scans revealed a crack in the tibia and hole at the top of his shin, which would have led to five more months out of action for the paceman.
For Harris, who took 113 wickets in 27 Tests after making his debut as a 30-year-old in 2010, it was one set of injuries too many after he endured a lengthy spell of rehabilitation following surgery on his right knee last year.
He also missed Australia`s recent test series win in the West Indies to attend the birth of his first child.
However, Harris -- a thorn in England`s side during the past two Ashes series where he took a combined 46 wickets -- said the likes of left-arm pacemen Mitchell Johnson and Mitchell Starc would lead the attack just fine as Australia went in search of their first away Ashes success in 14 years.
"I nearly blew my head up yesterday (Friday) thinking there must have been a way I can get around this as I have before, but on the other side, the last time was a struggle," Harris told reporters at Chelmsford.
"Now it was probably four to five months minimum before I could probably run again, when I would be 36 and at the end of the day, it was going to be hard for me, also to get back in the side I thought would be impossible.
"My wife saw what I had been through before and said `you can`t do that again`, but making the decision I have has not been easy, because I love doing what I do."
Former England captain Michael Vaughan said Harris`s loss would be a "massive blow" to Australia.
But Harris, who might not have featured in Cardiff even if he had been fully fit, wasn`t so sure.
"Am I going to be missed? I don`t think I am. Personally I don`t think I was going to be playing the first two Tests anyway, and when you chuck Mitch Johnson in there, with the guys we have got, they can do the job in any conditions.
"Starc has played here before in the last Ashes and also for Yorkshire, (Josh) Hazlewood has had a good bowl here and got better, Mitch has been here also, and so I think there will be some good experienced involved."
However, Australia captain Michael Clarke said Harris was his "number one pick bowler in any team I have played with".
Clarke added: "If I asked him to run through a brick wall for this team, I think he would have a crack at it and has always given his best.
"It is really important for us to celebrate an amazing career...He is as good as anyone to play for Australia."
Cricket Australia said Harris, who is now contemplating a career in coaching, would be replaced in the squad by 22-year-old paceman Pat Cummins.